In the course of giving numerous presentations to the public on exciting ideas in modern cosmology, eventually someone is going to ask you about how God fits into the picture. It's not obvious how to answer; this is the kind of thing cosmologists love to argue about at coffee breaks during conferences.

Of course, the first problem is what is the "right" answer, in terms of what the speaker actually believes. For me that's easy; I think the notion of God is an outdated fiction. (I understand that not everyone agrees.) But it doesn't obviously follow that you need to be so blunt to your audience. An argument could certainly be made that, if you were speaking to a polite group of people whom you knew to be religious, you might not want to distract from the purely scientific message by turning them against you with your godless atheism. This isn't to say you should be dishonest, but simply polite; there is no law of human interaction saying that we have to tell the full truth about every issue at every possible opportunity. (If there were, everyone in the world would be single.)

But increasingly I'm coming to believe that directness is the best policy when it comes to God and the universe. I will illustrate this unscientifically by a story. Some time back I visited DePauw University, a very religious Midwestern institution, to give an invited talk on cosmology and atheism. So, I was in a context where the issues couldn't be avoided; but I tried to defuse the situation by being friendly and non-confrontational, and was generally afforded a very polite reception (by these people who didn't believe a word I was saying).

It was after the talk that I learned something important. Several people came up to ask questions or simply make a comment, all of them unfailingly friendly. But one young woman in particular was very effusive in her thankfulness for the talk I had just given. It turns out that she was an undergraduate student there. As she explained it, for a long time she had been having doubts about religion and the existence of God, but had been reluctant to talk to anyone about them on this devoutly Methodist campus. She said that hearing my talk had been a revelation for her, as it put into words many of the ideas that had been floating around in her head. More importantly, it gave her courage to hear someone actually stand up and say them out loud in a public forum.

Usually my cosmology talks don't have such a dramatic effect on people. I guess the point is that we can worry so much about being polite to the people we disagree with, that we can shortchange the people who want to agree with us if we would only put our best arguments forward. I don't ever mention religion when I am giving pure science talks, but from now on I will be less reluctant to give blunt answers when someone asks me about it afterwards.